1. Field of the Invention
The present invention relates to indicia generally and especially to machine readable coded indicia, and more particularly, but not by way of limitation, to novel means and method for reading bar codes on substrates that may be skewed with respect to the means for reading the bar codes. More generally, the present invention relates to sensing the relationship of an edge of the substrate to the reading means.
2. Background Art
A need exists for being able to rapidly and accurately read indicia, such as bar codes, on substrates passing moving relative to a fixed reading head which substrates may be skewed with respect to the reading head so that the bar codes are also skewed with respect to the reading head. Such skewing may result in a portion or all or the bar code not being read.
One environment in which such a need exists is in the dispensing of travelers checks from automatic teller machines (ATMs). It is desirable to read identifying bar codes disposed on such checks as the checks are dispensed from the ATM. Such checks are dispensed quite rapidly and, being of fairly light weight and being mechanically handled in the ATM, they can easily become skewed with respect to a fixed bar code reading head in the ATM.
A further problem in such an environment is that the travelers checks may flutter as they pass the bar code reading head, which fluttering affects the focal point of the reading device.
An additional problem with such reading bar codes on travelers checks is in the physical size of bar code reading equipment that can be retrofitted to existing ATMs. Because of space limitations, conventional scanning bar code reading equipment cannot be easily employed. Also, scanning types of bar code reading equipment are relatively expensive.
Another problem related to size and configuration is that the bar codes on travelers checks are desirably of the invisible or nearly invisible type which require backlighting in the reading thereof. Backlighting cannot practicably be employed with conventional scanning techniques because, typically, the illuminating source moves with the light detector, a near impossibility within the space limitations of an ATM.
Accordingly, it is a principal object of the present invention to provide means and method for reading indicia printed on a substrate, which substrate may be skewed with respect to indicia reading means.
It is a further object of the invention to provide such means and method that permit rapid reading of such indicia.
It is an additional object of the invention to provide such means that can be easily retrofitted to existing ATMs.
It is another object of the invention to provide such means and method that can be employed to read invisible or nearly invisible indicia that require backlighting for the reading thereof.
It is yet a further object of the invention to provide such means and method that can prevent the fluttering of travelers checks as the bar codes thereon are read.
Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.